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Again, a problem with my Grand Marquis

I start the car and then when i put it in reverse or Drive, the motor stops. After it wont start. I wait 10 minutes, then it starts, i roll on the highway, and then at the first red light, the engine stops again... The starter works perfectly, in my Haines manual they say to chek the Relay...but in the 89' grand marquis, i dont find the relays(i dont think i have some).

I think it could be a bad ground at the fuel pump, but before taking the fuel tank down, i wanted to know what you think is wrong.

Sounds like a couple of different problems all happening together. When it cuts out and you say it won't start again, does the starter spin, or does nothing happen when you turn the key? If the starter is not spinning, the first thing I would check is the neutral safety switch, which might explain the fact that it won't start again until you wait awhile.

When the motor cuts out, do you have any electrical accessories working? I know I had a similar problem, and what was causing it was a frayed wire that was creating an intermittent open circuit. This wire was running from the starter relay (round thing with wires going to positive and negative terminals on the battery) around the back of the engine bay and into the passenger compartment through a rubber boot sort of near the steering column.

When you say the car works fine sometimes and other times not, it leads me to think electrical problems. I'm sure other people with more troubleshooting skills than I will chime in soon.

sounds to me as though the IAC valve is acting up and causing the stalling and the not wanting to restart might be due to a bad batter connection if stater will not turn. these cars are VERY picky about the battery connection in order to start them. my first CV would act like a dead battery and such and all i had to do was mess with where the battery cable connects to the battery to get it going.

Get yourself a multimeter and check your Engine Coolant Temp sensor (ECT), your throttle position sensor (TPS), and your idle air control (IAC).
Resistance across the terminals for the ECT should be high when the engine temperature is cold, and low when it is hot.

With the ignition on but the engine not running, the voltage drop from the +5v supply wire to the signal return wire should be between 0.2 and 1.4 volts with the throttle closed, and should be slightly lower than 4.8 at wide open throttle.

Resistance between the IAC terminals should be between 6-13 ohms. If you don't get a reading, swap the probes around on the terminals. There's a diode that only allows current to go one way in the IAC. It probably wouldn't hurt to pull the IAC and hit it with a bunch of carb cleaner. It's more than likely gummed up.

When you turn the ignition key to ON, but don't start the engine, you should hear a hum or whine from the rear of the car; that's the fuel pump. It'll probably shut off after a minute. If you don't hear that hum (it's pretty loud), there's something wrong with the fuel pump circuit or the pump itself. Listen for it when you're having trouble starting the car.

Sorry to whore in the thread, but I am having some of the same issues, and trying to work them out.

I am going to change the Ign. Module this weekend...I wonder...should I go ahead and pop for the pickup inside the distributor too? I understand you have to remove the dizzy and press the gear off, is this correct?

I don't have a VOM to check things.

Mine only quits after a long drive on a hot day with the A/C running, it'll just quit while I am going down the road.

I already pulled the UIM, and cleaned the throttle body, and the EGR valve and plate, and the IAC motor, it seems to idle a bit faster too now.

People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf. ~ George Orwell

Kind of the same thing, it is when I drive off the interstate, or if i put the pedal to the metal in my driveway and then let it go in one shot, the idle rpm seems to drop below the normal idling rpm, and a lot of times the motor then stops.

I know my readings from my ECT is a bit under specs, so i'll be changing it...but my hopes are not that great.

I tried to get the codes out of my OBD with my Voltmeter but I didint manage to get them. If someone got any tricks, feel free to help!

12 could be a vacuum leak, or a sticky IAC. Could also be the "idle screw" has been cranked out and the idle won't go down to normal.

45: this is the air injection crap that runs behind the head and down to the cat converter. It ties into the smog pump. 45 means either the smog pump isn't there, isn't hooked up, the diverter valve is bad, a broken vacuum line for the diverter valve, stuck control solenoid for the valve, or most common, the ports in the cylinder heads are just packed with carbon. Don't worry about this code, it doesn't really do much of anything. The air switches away from being pumped into the back of the heads after a minute or two of running anyhow.